Oxidation pathways of arachidonic acid and other polyunsaturated fatty acids are being investigated. Methods for the synthesis of fatty acid hydroperoxides and prostaglandin endoperoxides are being explored. Prostaglandin H2 and G2 have been prepared by chemical synthesis and these compounds have been studied extensively. Further, model reactions intended to mimic the biological conversions of these prostaglandin endoperoxides are under investigation.